The fact is, quadcopters get lost all the time. People send them up too far or the wind catches them or the pilot gets disoriented and the copter goes where you can no longer see it. There are no secret keys revealed in this Instructable, no set of buttons to push or joysticks to wiggle to magically make it come flying back to you. What follows is only a carefully considered and tested method along with some legal and personal advice for POSSIBLY finding the downed copter.
Step 1: DO NOT TURN OFF YOUR CONTROLLER!
One of your best bets for locating a lost Hubsan is by being able to hear its whiny props spinning. If you turn off your controller figuring, "Hey, it's lost, this won't do me any good now," you are wrong! You MUST keep the controller turned on (with the left joystick in the lowest position) to have any hope of finding your Hubsan by sound.
Step 2: I KNOW IT'S TOO LATE BUT JUST IN CASE!
If you are about to start looking for a lost Hubsan, it is too late for this step. But if you DO manage to recover it, the first thing you MUST do is write your name and phone number on it somewhere so that if you lose it AGAIN (which you will) and anyone finds it they can contact you! This puts at least SOME of the burden of recovery on the public, who are often quite willing to call up a stranger and report a lost toy (though I am sure this depends on the neighborhood where you lost it). Label your Hubsan. It may save it NEXT time you lose it!
Also what will help you: not flying it in conditions that are at all windy above 20 or 30 feet. I know you can't tell what the weather is like up there, but if you have any inkling that there might be breeze a-blowin', don't take your Hubsan out for a spin! It's a very little machine, and it cannot fight even a mild wind. Note that wind speeds tend to increase quickly with height, and that a "light breeze" at ground level is likely a "gusty day" at 40 feet. Avoid the wind. Next time.
Step 3: I Hope You Did This Already
You should have made a mental note of about where (in which compass direction) you lost your Hubsan. Once you started to lose it, you should have reduced the engines and let it come down quickly. And you should have noted about where it came down. This is your best reference for hoping to find it. If you know about which direction it was heading when it went down, you can look on Google Maps for your area and see what buildings or structures might be in that general direction. This can be a critical guide to the recovery process.
Also, keep this in mind: the human brain tends to interpret vertical distances as larger than horizontal ones (something about us having been arboreal primates who were led by evolution to fear falling from heights). A quadcopter that is 200 feet overhead when you kill the engines is going to be less than 200 feet away from you on the ground (for reasons of physics & geometry) as well as being actually closer to you than you think it should be, given how far "away" from you it seemed to be when you lost it. Bottom line: it's probably not as far away as you think it is (unless a strong wind has carried it away, in which case the preceding paragraph won't help much).
Step 4: Wander the 'Hood
What follows presupposes you have lost your copter in an urban environment. With your controller still turned on (yes? Wait, I know you didn't do this, but for next time) start walking as quickly as you can in the direction you think the Hubsan went down. Every few dozen yards or so, try pushing the throttle up. If the copter is within radio distance of your controller, its props will start to whir. Don't try to get it back in to flight just yet: it may have lost a prop or have other damage. You just want to find it for now, and if you kept your controller turned on, there is hope you will be able to hear it. Note that although the copter may sound loud to you up close, its high-pitched noise is very hard to hear beyond 30 or 40 feet for anyone. If you are further away than that, even if you have maintained radio contact and can start the engines, you won't hear them. Don't wear out the battery you still have in the copter! Do quick tests many yards apart in the direction you think it went down and see if you can hear it whirring.
Part of wandering the 'hood is having a sense of what that hood looks like from overhead. It may be useful to generate an aerial map of the space in which you think it went down, and then breaking this map down by terrain. For example, you can generate a JPG image of the map using a number of different apps, load the map into Photoshop or similar, and then start marking the objects you see like this:
- Trees & shrubs
- Building rooftops
- Slanted rooftops will tend to shed the Hubsan to the ground
- Flat rooftops or rooftops with only very gentle slopes will tend to hold on to it
- Pools or other bodies of water - in most neighborhoods, the probability of your Hubsan actually landing in someone's pool is actually very low, given the proportion of surface area they normally cover in a neighborhood
Noting the slopes of different rooflines may be particularly helpful, as these areas effectively become "It's not here" zones and the ground around them is where you may want to consider looking. In most urban environments, after you account for rooftops and trees, the largest open space in which you are likely to encounter your Hubsan is a public roadway, sidewalk, or someone's driveway/ front yard. If it has landed in one of these places, it will not be there long: if someone saw it come down, they are very likely to retrieve it out of curiosity. But if you act quickly, these are spaces where you can often get to easily yourself and retrieve the copter before anyone else does.
Step 5: Panic
The fact is, depending on the circumstances, there is a pretty good chance you have simply lost your Hubsan for good. If it landed on private property, you have no right to retrieve it— you can ask the residents of that property if they would please return it to you, but they are under no obligation to do so.
If you were flying your Hubsan over tall trees or near a body of water, you should almost certainly consider it lost. There is no harm in wandering around with the controller listening for it, of course, but lets' be realistic: you lost it because it got out of your control, and it went down "somewhere," and you are probably screwed on this one. Sorry, just trying to be honest.
Step 6: Waste Not a Moment!
Despite the previous step, the best chance you will have of recovering your Hubsan is the moment you lose it. Go looking for it immediately! This may seem like a hopeless task, and maybe it is, but your memory is freshest right now and the likelihood that it has been run over by a car or eaten by a dog or found and kept by a neighbor kid are LOWEST right now! The chance that it will eventually become damaged or found and discarded as garbage increases with each passing minute. You must look for it now. Right now.
Step 7: When Step Six Doesn't Work
So you've lost your Hubsan, and you looked for it, and you didn't find it. Canvasing is the only other remaining legitimate step to hope to recover it. Make signs that indicate the day and time that you lost it, make sure they include a photograph of the Hubsan model that you lost, and beg for help. Offers of reward are probably pointless since the toy isn't all that valuable in the first place, but supposedly never hurt. Put these signs up in the area where you think you lost it, and put them up FAST! The sooner they get put up, the better the chance that someone will find it and let you know If you wait even one full day, there is a good chance the unit has already been found and dealt with. Canvasing: it is pathetic, but as a last move, it may save you.
Step 8: A Pound of Cure
If you do get your Hubsan back, you might be thinking about wanting to attach a Bluetooth tracking device to it (such as the Tile or one of its analogs). Let me discourage you from bothering. These devices will work fine if you lose your Hubsan within 75 feet of where you are standing, and while that may seem like a fairly substantial range, in reality, it isn't. If you have taken your Hubsan up high enough and it has traveled far enough for you to lose it, it has probably gone further than 75 feet.
There is this: many of these devices are set up so that if they become separated from their paired phone by greater than 75 feet, they will begin to sound an alarm both on the phone and on themselves. So if you really take it up high and it goes more than 75 feet away from you, it will begin beeping. And that beeping will continue until you are close enough again to the device to shut it off. But you can't set up these devices to only activate once they have become "lost", you can only set them up to activate once they become "distant." In other words, you can't go, "Oh, sh!t, there goes my Hubsan! Let me turn on my phone and make it sound an alarm, it's gone really far away." If it has gone further than 75 feet, it is already sounding its alarm. And if it wasn't set up to sound that alarm at takeoff, then you can't make it sound the alarm once it is more than 75 feet away from you. Neither can you use such devices to locate your Hubsan on a neighborhood map: the signal they give off is too weak to be detected by any network, although if you are using an actual OEM Tile, there is a chance that another Tile user's phone may detect your Hubsan and send you a message as to its location. A chance. The Tiles cost $25 a piece (2016). You lose it AND the Hubsan in one go, and you've probably shot about $75 instead of just $50.